The primary goal of this group is to investigate the prophylaxis and management of infectious complications of cancer patients undergoing chemotherapy. A recently completed study was one of prophylaxis of infection in neutropenic patients with passive immunization. It was a randomized study of intravenous gammaglobulin (IVIG) versus placebo. Preliminary analysis in 75 patients randomized at the NCI and Naval Hospital, Bethesda, showed no differences between IVIG and placebo in incidence of fever, documented infection, or duration of fever. The present project is a randomized study of monotherapy (ceftazidime) versus ceftazidime plus vancomycin for the initial empiric therapy of febrile cancer patients with very low white blood counts. To date, 85 episodes have been analyzed between the two collaborating centers (NCI-NMOB and University of Florida; 20 episodes at NCI- NMOB).; Early results show a somewhat better initial response rate to combined therapy, but a very similar ultimate outcome in survival. The randomized study of ceftazidime plus/minus vancomycin is in progress. An early analysis of 85 episodes shows a higher initial response to the two drug regimen, but a similar ultimate outcome.